Q&A #409

Addition reversal problems

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From: Gail (for Teacher2Teacher Service)
Date: Jul 15, 1998 at 12:22:39
Subject: Re: Addition reversal problems

I would use unit blocks (ones, tens and hundreds blocks) to help the student understand that where the digits are in a number makes a difference in how much they are worth. If the student is adding 3 tens and 6 ones, and 2 tens and 4 ones, s/he can manually put the two groups together, and then note how many are in each place value group. If you give the student a grid to record the problem, with columns labeled hundreds tens ones they will have a way of recording their sums as they work. Giving them a set of problems to solve this way, and discussing what happens each time, is important in assisting them in understanding. Also, be sure to give them some problems that don't require regrouping the ones digit, too. Let them "discover" what happens when numbers are added. When they add and get an incorrect sum, model that sum, and let them determine why it couldn't be correct. -Gail, for the Teacher2Teacher service

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